Just saw this link and it seems that the migration is pretty seamless. https://www.sqlservercentral.com/blogs/migrating-from-evernote-to-joplin
A simple solution would be to ask Meta to opensource Facebook, WhatApp, Instagram and whatever their federated instance would be called code and in return, they can federate with the fediverse. I think that will show their true intentions on how much love they have for the opensource community. Put the ball in their court and if they agree, they will be welcomed to the fediverse as good faith actors.
Just my 2 cents.